Variable shape reflector



Oct. 7, 1969 F. D- AMBURGEY VARIABLE SHAPE REFLECTOR Filed Sept. 21, 1967 FIG. 4

FIG.3

INVENTOR. FLOYD D. AMBURGEY BY kgiw,

United States Patent 3,471,860 VARIABLE SHAPE REFLECTOR Floyd D. Amburgey, P.O. Box 1275, Sierra Vista, Ariz. 35635 Filed Sept. 21, 1967, Ser. No. 669,670 Int. Cl. H01q 15/20 US. Cl. 343--915 1 Claim ABSTRACT OF THE DISCLOSURE The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment to me of any royalty thereon.

This device provides a method of obtaining temporary or permanent surfaces of variable geometry for use as radiating, receiving and reflecting surfaces for electromagnetic waves.

The variable shape reflector antenna of this invention may be a laboratory, a field or a manufacturing tool. It also provides a means of varying the geometry of an electromagnetic receiving, radiating or reflecting surface (antenna reflector) such that the maximum gain or directivity can be obtained from any given signal over any given circuit. When used as a laboratory tool it provides empirical means of determining the most eflicient means of determining the most efiicient shape of a reflector. When employed in the field or for manufacturing, it provides a convenient and inexpensive means of engineering a. reflector for a given circuit.

The variable shape reflector antenna of this invention consists of three major parts; first, there is the reflector of flexible material with a highly reflective surface; second, there is the pressure or vacuum chamber behind the reflector; and third there is the pressure or vacuum pump connected to the chamber.

In the drawing:

FIGURE 1 is a perspective view of the front of the reflector antenna;

FIGURE 2 is a similar view of the back of the reflector of FIGURE 1;

FIGURE 3 is a diagrammatical side view of the antenna with the reflector in a convex shape extended to the limit of the flexible reflector material; and

FIGURE 4 is a view similar to FIGURE 3 with the dotted lines indicating the reflector in a concave shape indicating the opposite limit of the flexible reflector material.

Referring to the drawing, in which there is shown an air chamber which may be a pressure or a vacuum chamber having a port 11 and closed at the open end with a flexible reflector material 12 sealed on the periphery of the air chamber with a band 13. The flexible reflector 12 may be of any suitable material which in this example 3,471,869 Patented Oct. 7, 1969 is Saran wrap or foil. The port 11 is connected by a hose 14 to a pressure or vacuum pump (not shown) or as shown a rubber bulb 15 which will vary the pressure in the air chamber 10 to produce the various curvatures of the reflector 12.

In operation, the variable shape reflector is sealed to the rim of the air chamber which may be evacuated or pressurized for various shapes or curvatures of the flexible reflector. Thus the desired or the most favorable shape may be obtained by calculation or by testing until the strongest available signal is obtained if the reflector is connected in a circuit under test. Under certain conditions such as the use of the variable shape reflector in the laboratory or over certain circuits it is generally more advantageous to leave the reflector surface pliable so that the shape may be changed as desired or for future tests. However, having obtained the curvature for best reception the reflector may be fixed, as by spraying a fixing agent thereon or painting the reflector external surface with a compound, such as epoxy. With the reflector in a rigid shape, it may be removed, mounted in a frame and used as the actual reflector in a system or it can be used as a mold or pattern for the fabrication of additional re flectors utilizing that particular curvature.

While a circular reflector is illustrated and described, other shapes of reflectors may be employed, such as elliptical, rectangular or polygonal, as well as a combination of shapes where for example a circular reflector facing an elliptical reflector produces an image of another circular reflector.

In the foregoing, the preferred embodiment of this invention has been disclosed. However it is not intended that this invention be so limited to the specific illustration shown in the drawing. It will be apparent to those skilled in the art, that the shape of the reflectors as well as the curvature may be varied and a variety of equivalent reflector materials may be employed without departing from the spirit of the invention or exceeding the scope of the appended claim.

What is claimed is:

1. A method of regulating an antenna for improved reception comprising, utilizing for an antenna a flexible reflector backed by an air compartment, varying the curvature of the reflector within the limits of flexibility of the reflector material, regulating the degree of curvature of the antenna for best reception by the pressure in the air compartment behind the reflector, and spraying with a fixing agent the selected curvature of the reflector to impart permanency to the preferred shape.

References Cited UNITED STATES PATENTS 2,742,387 4/1956 Giuliani 343-912 2,948,896 8/1960 Hart 343-912 XR 2,952,189 9/1960 Pajes 350-295 3,001,196 9/1961 McIlroy et al. 343-915 3.273.157 9/1966 Kirstein 343--915 ELI LIEBERMAN Primarv Examiner M. NUSSBAUM. Assistant Examiner 

